Cutting or scoring balloons are known for opening occluded or constricted vessels of a patient, caused for instance by stenosis. Such balloons may have one or more blades or cutting elements fixed to or otherwise integral with the balloon wall, used for cutting or fragmenting stenosed material from the vessel wall. These balloons are generally effective in opening stenosed vessels. However, difficulties arise with the deployment of such balloons as a result of the risk of the balloon wall being cut or torn by the cutting or scoring elements. As a result, these balloons tend to be wrapped in such a manner that the balloon wall is kept away from the cutting or scoring elements when the balloon is in a deflated state. This may be by a particular balloon folding arrangement or by provision of a protective wrapping around the cutting or scoring elements. Whilst these methods may be effective in reducing the risk of damage to the balloon wall, they lead to a balloon which is loosely wrapped and which thus has a much greater delivery footprint (diameter) than simple medical balloons which are tightly wrapped onto the balloon catheter. A wider introducer assembly is harder to deploy endoluminally in a patient. Moreover, a balloon which has a greater deflated diameter is not suitable to treating heavily stenosed vessels, that is having only a small opening through the stenosed area, or for treating smaller diameter vessels.
Examples of prior art cutting or scoring balloons can be found for instance in U.S. Pat. No. 7,413,558 and U.S. Pat. No. 5,209,799. Apparatus for folding or wrapping standard balloon catheters can be seen, for example, in U.S. Pat. No. 7,762,804, U.S. Pat. No. 5,209,799, U.S. Pat. No. 7,618,252 and US-2005/0251194.